ANTIOCH — A 2-month-old boy was near death Thursday night, and his father was in jail after being arrested on suspicion of punching the boy in the face, police said.

Sigifredo Lua, 23, of Antioch, was being held on $1.1 million bail at County Jail in Martinez, and police have recommended charges of felony abuse with great bodily injury. The baby was alive Thursday night but not expected to recover. He was removed from a life-support machine Thursday afternoon, police said, and was in a vegetative state. Police said the baby’s brain stem, which controls breathing, is the only part of the child’s brain that is still functioning, and that the family has inserted a feeding tube.

Charges reflecting the baby’s anticipated death are expected to be considered today, said John Cope, the head of the Contra Costa County District Attorney’s homicide unit.

Investigators began unraveling the attack about 9 p.m. Tuesday, when doctors at Sutter Delta Memorial Hospital treated the 2-month-old boy who came to the hospital by ambulance and was unresponsive, suffering from major injuries.

They suspected child abuse, and called police.

The baby was transferred to Children’s Hospital Oakland, where he was treated for multiple fractures, a lacerated liver, and bleeding on the brain.

He was removed from life support and declared brain-dead, acting police Lt. Diane Aguinaga said.

An investigation revealed that before the boy was taken to the hospital, Lua was watching his two children at a house in the 700 block of O Street.

Lua called his wife at work to say that the 2-month-old was hurt, and she called 911, Aguinaga said.

Investigators said they found inconsistencies in Lua’s statements about how the child was injured and after further questioning, Lua confessed that he punched the baby in the face.

The case remains under investigation. Anyone with information can contact Detective Robert Green at 925-779-6932.

Staff writer Rick Hurd contributed to this story. Robert Salonga covers public safety. Contact him at 925-943-8013. Follow him at Twitter.com/robertsalonga.

Robert Salonga is a Pulitzer Prize-winning reporter covering criminal justice and public safety for The Mercury News. A San Jose native, he attended UCLA and has a Master's degree in journalism from the University of Maryland. He previously reported in Washington, D.C., Salinas and the East Bay, and is a middling triathlete. Reach him the low-tech way at 408-920-5002.